Investigation of self-heating effect on DC and RF performances in AlGaN/GaN HEMTs on CVD-Diamond
- Resource Type
- Authors
- Abhinay Sandupatla; Kumud Ranjan; Subramaniam Arulkumaran; Geok Ing Ng
- Source
- IEEE Journal of the Electron Devices Society, Vol 7, Pp 1264-1269 (2019)
- Subject
- Electron mobility
Materials science
02 engineering and technology
Chemical vapor deposition
High-electron-mobility transistor
01 natural sciences
DC
AlGaN/GaN
0103 physical sciences
RF and TCAD
Electrical and Electronic Engineering
HEMT
Power density
010302 applied physics
Condensed matter physics
Wide-bandgap semiconductor
self-heating
Biasing
CVD-diamond
021001 nanoscience & nanotechnology
Electronic, Optical and Magnetic Materials
Electrical and electronic engineering [Engineering]
Continuous wave
lcsh:Electrical engineering. Electronics. Nuclear engineering
0210 nano-technology
Joule heating
lcsh:TK1-9971
Biotechnology
- Language
- English
We have investigated the self-heating effect on DC and RF performances of identically fabricated AlGaN/GaN HEMTs on CVD-Diamond (GaN/Dia) and Si (GaN/Si) substrates. Self-heating induced device performances were extracted at different values drain bias voltage ( $V_{D}$ ) and dissipated DC power density ( $P_{D}$ ) in continuous wave (CW) operating condition. The effect of self-heating was observed much lesser in GaN/Dia HEMTs than GaN/Si HEMTs in terms of $I_{\mathrm{D}}$ , $I_{\mathrm{G}}$ , $g_{\mathrm{m}}$ , $f_{\mathrm{T}}$ and $f_{\mathrm{max}}$ reduction. Increased channel temperature caused by joule heating at high $P_{\mathrm{D}}$ reduces the 2-DEG carrier mobility in the channel of the device. This behaviour was also confirmed by TCAD simulation which showed ~3.9-times lower rising rate of maximum channel temperature and lowers thermal resistance ( $R_{\mathrm{th}}$ ) in GaN/Dia HEMTs than GaN/Si HEMTs. Small signal measurements and equivalent circuit parameter extraction were done to analyze the variation in performance of the devices. Our investigation reveals that the GaN/Dia HEMT is a promising candidate for high power density CW operation without significant reduction in electrical performance in a large drain bias range.